Alarm delay mechanism for alarm clock



Oct. 26, 1965 E. CIELASZYK 3,213,603

ALARM DELAY MECHANISM FOR ALARM CLOCK Filed March 4, 1964 4 Sheets-Sheet1 cfdward (:1 L e 1 353b Oct. 26, 1965 E. CIELASZYK 3,213,603

ALARM DELAY MECHANISM FOR ALARM CLOCK Filed March 4, 1964 4 Sheets'sheet 2 QR m rams Y/ Oct. 26, 1965 E. CIELASZYK 3,213,603

ALARM DELAY MECHANISM FOR ALARM CLOCK Filed March 4, 1964 4 Sheets-Sheet3 A F myzzm-romd u ward f: 6 J aJ'gfl K,

Oct. 26, 1965 E. CIELASZYK 3,213,603

ALARM DELAY MECHANISM FOR ALARM CLOCK Filed March 4, 1964 4 Sheets-Sheet4 6d ward C (62c: 135 k United States Patent 3,213,603 ALARM DELAYMECHANISM FOR ALARM CLOCK Edward Cielaszyk, Ogleshy, Ill., assignor toGeneral Time Corporation, New York, N.Y., a corporation of DelawareFiled Mar. 4, 1964, Ser. No. 349,236 8 Claims. (Cl. 58-18) The presentinvention relates to alarm clocks and more parlticularly to means forproviding a programmed alarm cyc e.

A popular feature of alarm clocks permits the user to sleep five or tenminutes after the alarm initially sounds. This may be accomplished bypressing a control on the clock shutting oif the alarm and setting up adelay cycle or the alarm cycle itself may be programmed within the clockto provide a few seconds of initial ringing followed by about tenminutes of silence before a sustained alarm is sounded. It is toprogrammed alarm mechanisms of this type that the present invention isdirected.

Thus it is an object of the invention to provide an alarm clock havingan improved mechanism for programming a short initial ringing of thealarm which is automatically terminated and which is followed, after adelay time interval, by the main or sustained ringing of the alarm. Itis another object of the present invention to provide an alarm programmechanism which is accurate and reliable and in which the initialringing interval and delay interval may be predetermined with a higherorder of accuracy than is usually possible in an inexpensive alarmclock. In one of the aspects of the invention it is an object to providea timing device embodied in an alarm of the vibrated clapper type inwhich the vibrated clapper serves as the escapement for the accuratetiming of the interval and in which the length of the interval may bereadily changed simply by changing the length of a drive segment.

It is another object of the present invention to provide an alarmprogram mechanism which is extremely simple, is long wearing and proofagainst misuse, and which may be added with only nominal expense toexisting designs of spring wound alarm clock mechanisms.

Other objects and advantages of the invention will become apparent uponreading the attached detailed description and upon reference to thedrawings in which:

FIGURE 1 is a perspective view of a clock mechanism employing theinvention, partly distorted and with portions broken away to reveal theinternal construction.

FIG. 1A is a fragmentary perspective showing the clapper and tripspring.

FIG. 2A is a fragmentary face view showing the trip member andassociated shift segment following winding and prior to ringing of thealarm.

FIG. 2B is a transverse section taken along the line 2B-2B in FIG. 2A.

FIG. 2C is a fragmentary side view of a dropoff cam.

FIGS. 3A and 3B correspond to FIGS. 2A and 23, showing the effect ofdropolf at the first step of the dropoff cam, with the trip memberreleased and with the alarm initially ringing.

FIGS. 4A and 4B are views corresponding to FIGS. 3A, 3B, but showing theposition of the shift segment at the end of its motion and with the tripmember cammed to its silencing position to begin the delay interval.

FIGS. 5A and 5B correspond to FIGS. 4A, 4B but show the positions of themembers upon dropoff at the second step of the dropoff cam and with thetrip member finally released for sustained ringing of the alarm.

FIG. 5C is a fragmentary view of the dropolf cam similar to FIG. 2C butshowing final dropoif.

While the invention has been described in connection with a preferredembodiment, it will be understood that 3,213,603 Patented Oct. 26, 1965I do not intend to be limited to the embodiment shown but intend tocover various alternative and equivalent constructions included withinthe spirit and scope of the appended claims.

Turning now to FIG. 1 there is shown an alarm clock 10 incorporating thepresent invention having an hour hand 11, a minute hand 12 and asettable indicator hand 13 arranged in front of the usual dial or bezel14, only a portion of which is shown. For the purpose of winding theclock a winding key 15 is provided. A setting knob 16, as will be seen,serves to set the timekeping hands 11, 12, as well as a settableindicator 13. An adjacent alarm disabling button 17 performs thefunction of turning the alarm off after it has served its purpose, itbeing understood that the button 17 remains in its pulled-out positionduring the normal operation of the clock and during the alarm cycle tobe described.

Certain portions of the clock mechanism shown in FIG. 1 will berecognized by one skilled in the art as conventional and it will thussuflice to describe such portions briefly. In the preferred embodiment asingle spring 20 is employed for driving the clock train and forpowering the alarm mechanism, the spring having its inner end connectedto a driving train output gear 21 and its outer end connected to analarm output gear 22 which is preferably of shallow cup shape to containthe spring. The alarm output gear 22 is rigidly connected to an alarmoutput pinion 23 by a shaft 24, the shaft also serving as a winding stemsupporting the key 15. To provide a ratchet for the spring 20, the alarmoutput gear 22 engages an alarm drive pinion 25 which is floatinglymounted and spring pressed into meshing position by a ratchet biasingspring 26. Thus when the key 15 is rotated in the direction shown, thealarm output gear 22 rotates, coiling the spring 20, the inner end ofwhich is held stationary by the drive train output gear 21 and withretrograde motion being prevented by the ratcheting pinion 25. Thespecial function of the alarm output pinion 23 during winding will bediscussed in detail at a later point.

A drive train, generally indicated at 30, serves to cou plc the outputgear 21, associated with the spring, to the escapement mechanism. Thusthe output gear meshes with a pinion 31 coupled to a minute wheel 32.Meshing with the wheel 32 is a first intermediate pinion 33 secured to afirst intermediate gear 34. The latter in turn meshes with a secondintermediate pinion 35 secured to a second intermediate gear 36. Meshingwith the latter is an escapement pinion 37 on an escapement wheel 38.The latter has an associated pin lever 39 under the control of a balancewheel 40 having the usual hair spring 41. It will be apparent, then,that with the spring balance properly adjusted the minute wheel 32 willturn at a timed rate, with the energy for the system being furnished bythe spring 20. For the purpose of connecting the minute wheel 32 to theminute hand 12 there is provided, at the rear end of the minute shaft46, a slip clutch of the coil spring type.

For driving the hour hand, a stepdown connection is provided including apinion 51 on the minute shaft meshing with a motion gear 52. The motiongear has a pinion 53 which meshes with an hour wheel 55 and which isconnected by a hollow shaft 56 to the hour hand 11. The stepdown gearingis of the usual 12:1 reduction ratio.

As stated, the alarm mechanism is powered by the same spring whichdrives the timing train. Thus, as shown in FIG. 1, the ratcheting pinion25, which meshes with the alarm output gear 22, drives a star wheel 61cooperating with an escapement 62 secured at one end of a clapper armbeing pivoted at 64 on the stem of the alarm disabling button 17. Theclapper 65 at the end of the arm cooperates with a bell 66 which may beof the usual cupshape partially enclosing the mechanism.

For the purpose of triggering the alarm at preset time, an indicatorwheel 7% is used which is coaxial with the hour wheel 55 and which isprovided with a pair of diametrically arranged dropoif cams '71, 72registering with dropoff openings 73, 74 formed in the hour wheel. Theindicator wheel 70 is coupled by means of a short collar to the alarmindicator 13 in order to indicate the point of dropoff. The indicatorwheel 70 is set by a setting pinion 75 on a setting stem 76, the pinionbeing biased toward the wheel by a spring 77. By pulling the settingknob 16 outwardly, the pinion 75 may be engaged with the motion gear 52for setting the clock hands, the setting movement being accommodated bythe slip clutch 4-5.

Means are provided for causing the cams 71, 72 to drop into the openings73, 74 arranged to receive them when the preset time is reached toeifect release of the alarm clapper for sounding the alarm. For thispurpose the hour wheel 55 is mounted for endwise movement and a tripspring 30 is provided which not only biases the hour wheel 55 but alsoprovides followup movement for release of the clapper. Thus the member80, which is in the form of an elongated leaf spring, is anchored at itsbase end 81 to the clock frame, the tip of the member being transverselybent to form a clapper engaging portion 82 which cooperates with alaterally bent lug 63a on the clapper arm. At the middle of the tripspring 8% a central clearance hole 83 is provided for clearing the shaft46.

Briefly stated, when the trip spring 80 is in its rearwardly pressedposition, as it is when the cams 71, 72 are riding high on the surfaceof the hour wheel 55, the portion 82 of the spring obstructs the lug 63aon the clapper arm maintaining the alarm silent. However, when the hourwheel 55 is gradually rotated around in a clockwise direction uponpassage of time, the point of dropoff is reached so that the cams 71, 72drop into the openings 73, 74 accompanied by forward movement of thehour wheel 55 and forward movement of the trip spring 80 therebyretracting the tip 82 of the spring away from the clapper arm to theposition shown in FIG. 3B and allowing the clapper to strike the bell66.

In a conventional alarm clock construction, the clapper once triggered,continues to ring the alarm until the shutoff plunger is pressedinwardly by the user of the clock or until the spring, which powers thealarm mechanism fully unwinds. However, in accordance with the presentinvention means are provided, responsive to the rotation of the springoutput pinion which accompanies the ringing of the alarm, for shuttingoff the alarm after ringing for only a few seconds. Means are furtherprovided for again turning on the alarm after a delay time interval ofsuitable duration, which may be on the order of 8l0 minutes, in order togive the user of the clock this much additional sleep. More specificallyin accordance with the invention, a dropoff cam is employed having afirst relatively shallow step which, upon dropoff, moves the trip springsufiiciently to release the alarm, with the resuting rotation of thespring output pinion being utilized to move a shift sector for restoringthe trip spring to its initial, disabling position. Moreover, thedropoif cam has a second, relatively deep, step which drops off severalminutes later and which results in sustained ringing of the alarm. Thusreferring to the drawings and particularly to FIGS. 2A and 2B, I haveprovided a program mechanism 90 which includes a shift segment 91 in theform of a flat plate of metal which is pivoted on a stud 92 and having acam 93 which is normally clear of the trip spring 80 but which, uponrocking of the shift segment about its pivot is brought into cammingengagement with the trip spring to restore the same to its alarmisablingposition. An arcuate slot 94 in the member 91 serves to clear the minuteshaft 46. For the purpose of rotating the shift segment upon initialtriggering of the alarm, the shift segment has a toothed segment or rack95 which meshes with the spring output pinion 23. The toothed segment issufficiently short so that its entire width is 4s traversed by thepinion 23 in only a few seconds time.

Means are provided for enabling the output pinion, which engages thesegment, to rotate far beyond the range of the segment incident towinding the clock and incident to the sustained ringing out of thealarm, with the excess movement of the pinion being idle as far as theshift segment is concerned, Thus in accordance with one of the aspectsof the invention, a centering spring is provided which urges the toothedsegment into a centered position with respect to the spring outputpinion so that when the latter rotates beyond the range of the segmentin either direction the additional rotation simply produces idleclicking of the segment and the segment is not driven beyond itsintended range. In the present instance, the centering action is broughtabout by use of a hairpin spring ltiti which has its apex coiled aboutthe stud 92 and which has legs 101, 102. which are biased inwardlyagainst the shaft 24 of the spring output pinion 23. The legs of thespring are prevented from springing inwardly by means of a stop member103 formed on the shift segment hi. It will be apparent, then, that theshift segment tends to remain in its alined position so that when thespring output pinion 23 is rotated in either direction beyond the rangeof the segment, the final tooth of the segment will, nevertheless,remain in engagement with the pinion, clicking idly as the pinionrotates but in readiness for meshed engagement with the pinion when thepinion rotates in the opposite direction.

The operation of the program mechanism 9i), and particularly the shiftsegment 91, will be apparent upon review of the stop motion diagrams setforth in FIGS. 2A- 5A and the corresponding FIGS. 2B5B respectively.Thus, referring first to FIGS. 2A, 2B, the condition there shown is thatfollowing the winding of the clock, for example, the evening before thealarm is to ring. The dropoff cam 71 on the indicator wheel 70 is out ofregister with the opening 73 in the hour wheel so that the hour wheeloccupies a high riding position in which the trip spring 8%) is pressedinwardly with the tip 82 blocking the movement of the clapper (FIG. 1A).Since the spring output pinion 23 is secured to the end of the windingstem, and since the winding stem is rotated counterclockwise, as viewedfrom the front of the clock, it is apparent that the winding will havethe effect of depositing the shift segment in its lower or cockedposition and with idle clicking occurring at the end tooth a of thesegment until the spring 2% is fully wound. Under such conditions thecam 93 on the shift segment is in its retracted or clear position.

In carrying out the invention, the dropoff cams, as shown in FIG. 2Chave first and second steps of dropoff, the cam 71 thus having a shallowstep 71a and a deeper step 71b. Accordingly, when the set time isreached, initial dropofi occurs as shown in FIGS. 3B and 4B, resultingin limited endwise movement of the hour wheel 55 and with followupmovement of the trip spring 30 in the releasing direction. This retractsthe tip 82 of the trip spring from the clapper, allowing the clapper tovibrate against the bell 66 upon rotation of the star wheel til. As thespring 20 unwinds, accompanied by rotation of the alarm output gear 22,the shaft 24 on which the output gear 22 is mounted rotates therebyrotating the alarm output pinion 23 clockwise. Since the end tooth 95aof the segment is in engagement with the pinion, the segment immediatelymeshes with the pinion and begins to rotate in the counterclockwisedirection. As shown in FIG. 3A, the segment is at the mid position ofthe pinion and moving toward the end condition set forth in FIG. 4A.During the last portion of the counterclockwise movement of the shiftsegment, the cam surface 93 engages the trip spring, camming itrearwardly in the alarm disabling direction. This causes the tip 82 ofthe trip spring to be gradually moved from the position shown in FIG.313 to the position in which the clapper is engaged and immobilized.

As the shift segment approaches the end of its range, the final tooth95b of the segment remains in clicking engagement with the pinion 23under the urging of the leg 102 of the centering spring 101). With theclapper immobilized there is no further rotation of the pinion 23. Thealarm is thus disabled after ringing only a few seconds, and the shiftsegment, in the condition shown in FIGS. 4A, 4B, has thus performed itsfunction. The alarm star wheel 61 and its escapement lever 62, inaddition to powering the clapper, perform the incidental function ofmeasuring out, rather accurately, a short space of time on the order ofa few seconds. Thus the period during which the alarm initially soundsmay be accurately predetermined simply by varying the width, i.e., thenumber of teeth in segment 95 and the degree of overlap of the tip 82with respect to the lug 63a of the clapper.

It may be noted that, unlike certain alarm delay mechanisms intended forthe purpose of giving the user an additional period of sleep, thepresent mechanism is entirely automatic and does not require the user totouch any control member on the clock in order to initiate the delayinterval.

Upon expiration of the delay interval, relative movement of the hourWheel 55 occurs permitting dropoff at the second step 71!). The delayinterval, which is preferably on the order of 8-10 minutes, isdetermined by the distance w between the first step 71a and the secondstep 71b (see FIGS. 2C and 5C). When dropoff at the second step occurs,the parts occupy the position shown in FIGS. 5A, 5B. After dropoif atthe final step 71b, the hour wheel 55 is in its fully advanced positionand followup movement of the trip spring 80 results in retraction of thetip 82 of the trip member from the clapper, freeing the clapper forvibration against the bell 66. It may be noted in FIG. 58 that thisfreeing action occurs notwithstanding the fact that the cam 93 on theshift segment 91 is still in its active camming position. Thus it isimportant that the second step 71b have a step which is greater than thethrow of the cam 93 on the shift segment so that the action of the cam93 is, in effect, overpowered or nullified to produce sustained ringing.

To summarize, then, the first step 71a on the dropoif cam initiatesringing of the alarm which initiates rotation of the spring outputpinion 23 and which causes movement of the shift segment 91 resulting inthe cam 93 of the latter restoring the trip spring 80 to its disablingposition after a few seconds ringing. Then, when dropoir occurs at thesecond step 71b, movement of the hour wheel, and the followup movementof the trip spring, produces final release of the clapper,notwithstanding the then position of the shift segment, until the alarmis manually shut off or until the spring which powers the alarm runsout. In the present clock, manual shutoff is achieved by pressing theshutoff plunger 17 which causes the whole clapper arm 63 to be movedinwardly so that the lug 63a thereon moves into disabling engagementwith respect to the tip 82 of the trip spring.

Means are provided for limiting the sustained sounding of the alarm inthe event that the disabling plunger is not operated, which isparticularly desirable where the energy for driving the clock train andfor driving the alarm are both obtained from a single spring. Thus arotation limiting means 110 is provided including a pinion 111 coupledto the output pinion 23 and an idler 112 meshing therewith. Frictionallycoupled to the idler 112 is a disabling disc 113 having a dog 114.Briefly stated, when the idler rotates through a full revolution, thedog 114 on the disc 113 drops into blocking engagement with the teeth ofthe pinion 111 preventing any further rotation in that direction. Thislimits the final ringing of the alarm to an amount which depends uponthe relative pitch diameters of the pinion 111 and idler 112 and whichmay be on the order of a half minute. For the purpose of causing the dogto be active in only one direction, i.e., the

direction of unwinding movement of the pinion 111, the disabling disc113 is provided with a shielding lug 115 on one side of the dog andwhich is laterally bent to cooperate with a small diameter hold-off discwhich forms a part of pinion 111. Thus during winding of the clock theshielding lug 115 engages the hold-oft disc 116 preventing the dog 114from acting. Since there is no shielding lug on the opposite side of thedog, the dog 1s fully operable to produce limited rotation for theunwinding direction of rotation of the pinion 111.

After the alarm has been either manually or automatically shut off,further rotation of the hour wheel 55 causes the dropoif cams 71, 72 toride out of their registering openings thus restoring the hour wheel andindicator wheel to the spread apart condition illustrated in FIG. 2B.This movement is, however, idle as far as shut off is concerned. Whenthe clock is next wound, for example, the following evening, therotation of the spring output pinion 23, which accompanies the Winding,causes the shift segment to be meshingly engaged with the pinion so thatthe first rotation or two of the pinion causes the shift segment to bedeposited, again, in the armed position illustrated in FIG. 2A inreadiness to respond to ringing of the alarm the following morning.Since alarm clocks of the present type require winding once a day, thisinsures that the shift segment will be moved to its armed position eachtime without care or thought on the part of the operator. Thus theoperation, including the meaurement of the initial ring interval andmeasurement of the delay interval, is both reliable and precise.

It is one of the noteworthy features of the present construction thatthe present invention may be incorporated in clocks of known designsimply by adding a few mechanical elements and without requiring anysubstantial modification of the existing structure. Thus in the presentinstance the shift segments 91 is rotatably mounted on a small auxiliarystud 92 and interposed between the hour wheel 55 and the trip spring 80.The teeth on the shift segment are tailored to mesh with teeth of asimple pinion 23 pressed on the end of the shaft 24 which forms anextension of the winding stem. The centering spring may be convenientlybuilt into the shift segment as shown in the drawings. This leaves, asthe only further requirement, provision for successive endwise movementof the hour wheel 55 at successive, slightly spaced conditions ofregister with the indicator disc 70, which is achieved in the presentinstance by forming steps of dropoif on the dropoff carn. Accordingly itwill be seen by one skilled in the art that the alarm programming anddelay feature has been brought about by addition of elements costing buta few cents for manufacture and installation, a cost which is greatlyoutweighed by the automatic delay feature.

While the means for providing an accurately predetermined interval uponinitial triggering of the mechanism has been here usefully applied inthe programming of an alarm mechanism, nevertheless it will be apparentto one skilled in the art that the shift segment and its associatedparts, shown and described herein, may be used, if desired, forperforming other functions as, for example, the operation of electricalcontacts without departing from the invention. As stated, since the starwheel and clapper mechanism is an escapement capable of measuring shortintervals of time, and since the rotation of the shift segment isprecisely proportional to the rotation of the star wheel, being drivenfrom the same shaft, the present invention enables automatic measurementof a time interval with an inherent accuracy of a fraction of a secondwhich may be desirable for more precise applications.

Also it will be apparent to one skilled in the art that while a dropoffcam having two steps constitutes a significant part of the presentinvention, nevertheless equivalent mechanism may be substituted at thispoint capable of responding to two successive conditions of registerbetween the hour wheel, or timing train, on the one hand, and theindicator wheel, or other settable member, on the other, again withoutdeparting from the present in vention.

Moreover, while the invention has been described in connection withobtaining an initial ringing on the order of a few seconds and aninitial delay period on the order of a few minutes, it will be apparentto one skilled in the art that these times may be adjusted to thefunction to be performed and it is, as a matter of fact, one of thefeatures of the present invention that the intervals may bepredetermined over a wide range simply by adjusting the dimensions ofthe parts.

It will be further apparent to one skilled in the art that while thepresent construction includes a rockable shift member, it is notessential to the present invention that such member be rockable and, ifdesired, the toothed segment 95 could be in the form of a straight rackwith the member 91 guided for straight line movement. However, rockablemounting for the shift segment 91 is preferred since this avoidsnecessity for guiding means and since it precludes the possiblity ofbinding and requires substantially no lubrication.

While the invention has been described in connection with a clock havinga single spring for powering the driving train and alarm, it will beapparent that the invention is not limited thereto but is applicable toclocks in which separate springs are used and where the alarm spring hasan output pinion for driving the shift segment.

In the following claims the reference to indicating hands is to thehands or other suitable time indicating means providing part of theclock. The terms indicator wheel and hour wheel are intended to refer tomembers which are stationary and driven respectively and which triggerthe alarm upon achieving a position of register.

I claim as my invention:

1. In a clock, the combination comprising, a clock mechanism having anescapement and indicating hands together with an interposed drive trainincluding an hour wheel, indicator wheel coaxial with the hour wheel,the hour wheel being relatively axially movable and biased with respectto the indicator wheel, a dropolf cam interposed between the indicatorwheel and hour wheel and having a first dropoif step, an alarm mechanismincluding a spring having a spring output pinion and clapper, a tripmember for the clapper normally occupying a clapper silencing positionsaid trip member having means for moving the same from the silencingposition in response to relative axial movement between the hour wheeland indicator wheel upon dropoff at the first step of the cam under thebias force existing between said wheels, means responsive to theresulting rotation of the spring output gear occurring incident toringing of the alarm for a few seconds duration for restoring the tripmember to its silencing position for shutting ofi the alarm, saiddropoff cam having a second step physically spaced from the first stepby an amount corresponding to a delay time interval of a few minutesduration for producing a second step of relative axial movement of thehour wheel for finally releasing the trip member and associated clapperfor extending ringing of the alarm.

2. In a clock, the combination comprising, a clock mechanism having anescapement, indicating hands and an interposed driving train includingan hour wheel, an indicator wheel settable with respect to the hourwheel, an alarm mechanism including a spring having a spring outputpinion and clapper, trip means for maintaining the clapper normallysilenced, means responsive to a first step of registration between thehour wheel and indicator wheel upon passage of time for releasing thetrip means and associated clapper for initiating the ringing of thealarm, means responsive to the rotation of the spring output pinionaccompanying a few seconds ringing of the alarm for restoring the tripmeans to its silencing (J condition, means responsive to a second stepof registration between the indicator wheel and the output wheel uponfurther passage of time and occurring a few minutes after said firststep of registration for finally releasing the trip means for sustainedringing of the alarm.

3. In a clock, the combination comprising, a clock mechanism having anescapement and indicating hands together with an interposed drive train,a settable indicator wheel coaxial with the hour wheel, said hour wheelbeing relatively axially movable and biased with respect to theindicator wheel, a dropoff cam interposed between the indicator wheeland hour wheel having a first dropoif step, an alarm mechanism includinga spring having a spring output pinion and clapper, a trip memberassociated with the clapper normally occupying a silencing position andresponsive to the relative axial movement between the hour wheel andindicator wheel upon dropoff at said first step to release the clapper,a shift segment meshing with the spring output pinion, a cam interposedbetween the segment and trip member for restoring the trip member tosilencing position upon predetermined limited rotation of the springoutput pinion thereby limiting the initial ringing of the alarm to a fewseconds duration, said dropotf cam having a second dropoff step spacedfrom the first step by an amount corresponding to a delay time intervalof a few minutes duration for producing a second step of relative axialmovement of the hour wheel for finally releasing the trip member forsustained ringing of the alarm.

4. In a clock, the combination comprising, a clock mechanism having anescapement and indicating hands together with an interposed drive trainincluding an hour wheel, a settable indicator wheel coaxial with thehour wheel, the hour wheel being relatively axially movable and biasedwith respect to the indicator wheel, a dropoff cam interposed betweenthe indicator wheel and hour wheel and having a first dropoff step, analarm mechanism having a clapper, a spring having a drive train outputgear coupled to the drive train and an alarm output pinion coupled tothe alarm mechanism, a trip member normally occupying a clappersilencing position and responsive to relative axial movement between thehour wheel and the indicator wheel upon dropotf at the first step torelease the clapper, a shift segment meshing with the alarm outputpinion, a cam on the shift segment for camming the trip member back tosilencing position, the shift segment having a limited number of teethso that the initial ringing of the alarm is limited to a few secondsduration, said dropolf cam having a second step spaced from the firststep by an amount corresponding to a delay time interval of severalminutes duration for producing a second step of relative axial movementof the hour wheel for finally releasing the trip member for sustainedringing of the alarm.

5. In a clock, the combination comprising, a clock mechanism having anescapement and indicating hands together with an interposed drive trainincluding an hour wheel, a settable indicator Wheel coaxial with thehour wheel, said hour wheel being relatively axially movable and biasedwith respect to the indicator wheel, a dropoff cam interposed betweenthe indicator wheel and hour wheel having a first dropoff step, an alarmmechanism including a spring having an output pinion and clapper, a tripmember for the clapper normally occupying a clapper silencing positionand responsive to the relative axial movement between the hour wheel andindicator wheel upon dropoff at the first step to release the clapper, ashift segment meshed with the spring output pinion for movement to aretracted position upon winding the spring and for movement to anadvanced position upon unwinding of the spring incident to initialringing of the alarm, a cam interposed between the segment and tripmember for restoring the trip member to silencing position as thesegment advances thereby limiting the initial ringing of the alarm to afew seconds duration, said dropotf cam having a second step spaced fromthe first step by an amount corresponding to a few minutes delayinterval for producing a second step of relative axial movement of thehour wheel for finally releasing the clapper for sustained ringing ofthe alarm, said segment having a biasing spring for biasing it into meshwith the spring output pinion and for producing idle clicking betweenthe segment and the teeth of the output gear when the latter is rotatedbeyond the range of the segment.

6. In a clock, the combination comprising, a clock mechanism having anescapement and indicating hands together with an interposed drive trainincluding an hour wheel, a settable indicator wheel coaxial with thehour wheel, said hour wheel being relatively axially movable and biasedwith respect to the indicator wheel, a dropoff cam interposed betweenthe indicator wheel and hour wheel having a first dropott step, an alarmmechanism including a spring having an output pinion and clapper, a tripmember for the clapper normally occupying a clapper silencing positionand responsive to the relative axial movement between the hour wheel andindicator wheel upon dropoif at the first step to release the clapper, apivoted shift segment meshed with the spring output pinion for rockingmovement to a retracted position upon winding the spring and formovement to an advanced position upon unwinding of the spring incidentto initial ringing of the alarm, a cam interposed between the segmentand trip member for restoring the trip member to silencing position asthe segment advances thereby limiting the initial ringing of the alarmto a few seconds duration, said dropotl cam having a second step spacedfrom the first step by an amount corresponding to a few minutes delayinterval for producing a second step of relative axial movement of thehour wheel for finally releasing the clapper for sustained ringing ofthe alarm.

7. In a clock, the combination comprising, a clock mechanism havingindicating hands and a driving train, an alarm setting member, an alarmmechanism including a spring, output pinion, star wheel, and clapper,trip means for the clapper normally occupying a clapper silencingposition and responsive to a condition of register between the settingmember and an element in the driving train for releasing the trip means,a shift segment meshed with the spring output pinion for movement withthe latter to a retracted position upon winding the spring and formovement to an advanced position upon unwinding of the spring incidentto ringing of the alarm, restoring means on the segment for restoringthe trip member to silencing position as the segment advances to stoprotation of the alarm output pinion thereby to define a time intervaldetermined by the length of the segment and period of vibration of theclapper, said segment having a biasing spring tending to urge thesegment into centered position with respect to the output gear toproduce idle clicking of the segment when the output gear is rotatedbeyond the range of the segment when the spring is wound while insuringmeshing of the segment and output gear when the spring unwinds.

8. In a clock, the combination comprising, a clock mechanism havingindicating hands and a driving train, an alarm setting member, an alarmmechanism including a spring, spring output pinion, star Wheel, andclapper, trip means for maintaining the clapper normally silenced, meansresponsive to a condition of register between the driving train forreleasing the trip means and associated clapper for initiating theringing of the alarm, means responsive to rotation of the spring outputpinion accompanying a few seconds ringing of the alarm for restoring thetrip means to its silencing position and for stopping rotation of theoutput pinion thereby to define a short accurately predetermined timeinterval.

References Cited by the Examiner UNITED STATES PATENTS 1,663,710 3/28Kopatschek 58-l8 X LEO SMILOW, Primary Examiner.

1. IN A CLOCK, THE COMBINATION COMPRISING, A CLOCK MECHANISM HAVING ANESCAPEMENT AND INDICATING HANDS TOGETHER WITH AN INTERPOSED DRIVE TRAININCLUDING AN HOUR WHEEL, INDICATOR WHEEL COAXIAL WITH THE HOUR WHEEL,THE HOUR WHEEL BEING RELATIVELY AXIALLY MOVABLE AND BIASED WITH RESPECTTO THE INDICATOR WHEEL, A DROPOFF CAM INTERPOSED BETWEEN THE INDICATORWHEEL AND HOUR WHEEL AND HAVING A FIRST DROPOFF STEP, AN ALARM MECHANISMINCLUDING A SPRING HAVING A SPRING OUTPUT PINION AND CLAPPER, A TRIPMEMBER FOR THE CLAPPER NORMALLY OCCUPYING A CLAPPER SILENCING POSITIONSAID TRIP MEMBER HAVING MEANS FOR MOVING THE SAME FROM THE SILENCINGPOSITION IN RESPONSE TO RELATIVE AXIAL MOVEMENT BETWEEN THE HOUR WHEELAND INDICATOR WHEEL UPON DROPOFF AST THE FIRST STEP OF THE CAM UNDER THEBIAS FORCE EXISTING BETWEEN SAID WHEELS, MEANS RESPONSIVE TO THERESULTING ROTATION OF THE SPRING OUTPUT GEAR OCCURRING INCIDENT TORINGING OF THE ALARM FOR A FEW SECONDS'' DURATION FOR RESTORING THE TRIPMEMNER TO ITS SILENCING POSITION FOR SHUTTING OFF THE ALARM, SAIDDROPOFF CAM HAVING A SECOND STEP PHYSICALLY SPACED FROM THE FIRST STEPBY AN AMOUNT CORRESPONDING TO A DELAY TIME INTERVAL OF A FEW MINUTES''DURATION FOR PRODUCING A SECOND STEP OF RELATIVE AXIAL MOVEMENT OF THEHOUR WHEEL FOR FINALLY RELEASING THE TRIP MEMBER AND ASSOCIATED CLAPPERFOR EXTENDING RINGING OF THE ALARM.